Leptin受体三种亚型在大鼠垂体前叶的表达及其对大鼠生长激素细胞胞内游离钙的影响

THREE SUBTYPES EXPRESSIONS OF LEPTIN RECEPTOR IN THE RAT ANTERIAR PITUITARY AND INFLUENCE OF LEPTIN ON INTRACELLULAR FREE Ca^(2+) OF THE RAT GROWTH HORMONE CELL

目的观察Leptin受体(OBR)在雄性大鼠垂体前叶中的表达,研究Leptin对大鼠垂体生长激素细胞胞内游离钙水平的影响。方法用RTPCR方法检测Leptin受体几种形式在大鼠垂体前叶中的表达,用梯度离心的方法分离垂体生长激素(GH)细胞,将Leptin作用于分离的生长激素细胞,检测生长激素细胞胞内钙水平的变化。结果用RTPCR方法检测到在雄性大鼠垂体前叶中有Leptin受体(包括通用型OBR,短型OBRa及长型OBRb)的表达。用Percoll梯度离心法分离出的生长激素细胞约占70%～80%,10-8mol/LLeptin作用于分离培养的生长激素细胞,可引起生长激素细胞[Ca2+]i相对水平迅速降低。结论在雄性大鼠垂体前叶有Leptin受体三种亚型的表达,且Leptin在体外可明显降低大鼠生长激素细胞胞内游离钙的相对水平。

Aim: To observe the expression of Leptin receptors (OB R) in male rat anteriar pituitary, and study the influence of Leptin on the level of intracellular free Ca 2+ ([Ca 2+ ]i) in the cultured growth hormone (GH) cell of male rat pituitary. Methods: RT PCR method was used to observe the expression of Leptin receptors (OB R) in male rat anterior pituitary. We used grade centrifuging method to get growth hormone (GH) cell, and [Ca 2+ ]i in GH cell was examined by laser scanning confocal system. Results: OB R mRNA were expressed in male rat anteriar pituitary, including OB R (common form), OB Ra (short form) and OB Rb(long form). There were about 70% or 80% GH cell by grade centrifuging. Leptin at 10 -8 mol/L could decrease the level intracellular free Ca 2+ ([Ca 2+ ]i) in cultured GH cell. Conclusion: There are three subtypes of Leptin receptors expressions in male rat anteriar pituitary, and Leptin could reduce intracellular free Ca 2+ level of GH cell markedly.